Merge branch 'net-fec-fix-to-suspend-resume-with-mac_managed_pm'

John Ernberg says:

====================
net: fec: Fix to suspend / resume with mac_managed_pm

Since the introduction of mac_managed_pm in the FEC driver there were some
discrepancies regarding power management of the PHY.

This failed on our board that has a permanently powered Microchip LAN8700R
attached to the FEC. Although the root cause of the failure can be traced
back to f166f890c8f0 ("net: ethernet: fec: Replace interrupt driven MDIO
with polled IO") and probably even before that, we only started noticing
the problem going from 5.10 to 6.1.

Since 557d5dc83f68 ("net: fec: use mac-managed PHY PM") is actually a fix
to most of the power management sequencing problems that came with power
managing the MDIO bus which for the FEC meant adding a race with FEC
resume (and phy_start() if netif was running) and PHY resume.

That it worked before for us was probably just luck...

Thanks to Wei's response to my report at [1] I was able to pick up his
patch and start honing in on the remaining missing details.

[1]: https://lore.kernel.org/netdev/1f45bdbe-eab1-4e59-8f24-add177590d27@actia.se/

v3: https://lore.kernel.org/netdev/20240306133734.4144808-1-john.ernberg@actia.se/
v2: https://lore.kernel.org/netdev/20240229105256.2903095-1-john.ernberg@actia.se/
v1: https://lore.kernel.org/netdev/20240212105010.2258421-1-john.ernberg@actia.se/
====================

Link: https://lore.kernel.org/r/20240328155909.59613-1-john.ernberg@actia.se
Signed-off-by: Jakub Kicinski <kuba@kernel.org>